Metal smart card with dual interface capability

ABSTRACT

A transaction card comprising a metal layer. A first cut out region in a first surface of said metal layer has a depth less than the thickness of the metal layer, and a first portion of an integrated circuit (IC) module is secured therein. A second cut out region extends from the first cut out region to the second surface of said metal layer and defines a non-RF-impeding volume having a perimeter greater than the perimeter of the first cut out region. One or more additional layers are stacked on the second surface of the metal layer, and a channel extends between one of the stacked layers and the IC module.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of PCT International Application No.PCT/US 2019/012685, filed Jan. 8, 2019, titled DUAL INTERFACE METALSMART CARD WITH BOOSTER ANTENNA, which claims priority from U.S.application Ser. No. 15/976,612, filed May 10, 2018 (status: granted asU.S. Pat. No. 10,318,859), which is a continuation-in-part of U.S.application Ser. No. 15/742,813, titled METAL SMART CARD WITH DUALINTERFACE CAPABILITY, filed Jan. 8, 2018 (status: granted as U.S. Pat.No. 10,289,944), which is a U.S. national phase application of PCTInternational Application No. PCT/US 2015/039535, filed Jul. 8, 2015.This application is also continuation-in-part of U.S. application Ser.No. 16/739,211, filed Jan. 10, 2020 (status: allowed), which is acontinuation of U.S. application Ser. No. 16/367,595, filed Mar. 28,2019 (status: granted as U.S. Pat. No. 10,534,990 on Jan. 14, 2020),which is a continuation of U.S. application Ser. No. 15/742,813. All ofthe foregoing are incorporated by reference herein.

BACKGROUND OF THE INVENTION

Smart cards are highly desirable and are in wide use, including: inpayment and ticketing applications, such as mass transit and motorwaytolls; in personal identification and entitlement schemes on regional,national, and international levels; in citizen cards; in drivers'licenses; in patient card schemes; and in biometric passports to enhancesecurity for international travel.

A smart card is a card that includes embedded electronic circuitry suchas an integrated circuit (IC) chip that connects or couples to a cardreader with direct physical contact and/or with a remote contactlessradio frequency interface. There are generally three categories of smartcards referred to herein as (1) contact, (2) contactless and (3) dualinterface.

A “contact” smart card includes an IC chip connected to a conductivecontact plate on which are mounted a number of physical contact pads(typically gold plated) located generally on the top surface of thecard. A contact smart card is inserted into a contact type smart cardreader and transmits commands, data, and card status over the physicalcontact pads.

A “contactless” smartcard contains an IC chip and a card antenna and isconfigured for coupling of RF signals between the smart card's IC chipand the antenna of a card reader. This permits wireless (e.g., RF)communication between the card and a card reader with no directelectrical contact between the card and the card reader. A contactlesssmart card requires only close proximity to a reader. Both the readerand the smart card have antennae, and the two communicate using radiofrequencies (RF) over a contactless link. Most contactless cards alsoderive power for the internal chip from electromagnetic signals emittedby the card reader. The range of operation may vary from less than aninch to several inches.

A “dual-interface” smart card has, typically, a single IC chip (butcould have two) and includes both contact and contactless interfaces.With dual-interface cards, it is possible to access the IC chip(s) usinga contact and/or a contactless interface.

It has also become very desirable and fashionable to make cards with oneor more metal layers. A metal layer provides a desirable weight and adecorative pattern and/or reflective surface enhancing the card'sappearance and aesthetic value. This is especially desirable for use byhigh-end customers. It is therefore desirable to make dual interface(contacts and contactless) smart cards having a metal layer.

However, several problems arise in the making of dual interface(“contactless” and “contact”) smart cards with a metal layer because ofconflicting requirements. By way of example, to construct a dualinterface smart card, the contact pads associated with the IC chip willbe located along an external surface (top or bottom, but normally top)of the card to make contact with a contact card reader and the IC chipwill generally be located near the top surface. However, any metal layerin the card interferes with radio-frequency (RF) communication signals(e.g., attenuates) between the card and the reader, and this may renderthe contactless smart card useless. So, a dual interface smart card witha metal layer ideally minimizes RF interference with respect to the ICchip. Compounding the problem is the desire for the dual interface metalsmart card to have a highly sophisticated appearance. Due to theprestige and aesthetic aspect of these cards, the contact pads desirablyhave an aesthetically pleasing interface with the card surface.

SUMMARY OF THE INVENTION

One aspect of the invention is a card having a card length, a cardwidth, and a card thickness. The card comprises a metal layer having atop surface and a bottom surface extending parallel to each other. Anopening in said metal layer (a) extends from the top surface to thebottom surface or (b) is defined by a first region cut out region in thetop surface of the metal layer and a second cut out region extendingfrom the bottom surface of the metal layer and extending verticallybelow the first cut out region and generally in a symmetrical mannerwith respect to the first cut out region. An integrated circuit (IC)module having a depth D1, a first area, and a first perimeter isdisposed within the opening or the first cut out region. The IC modulehas contacts positioned along the top surface of the metal layer and isconfigured to communicate using RF transmission to enable contactlessoperation. A plug formed of non-RF-impeding material is disposed withinthe opening or the second cut out region, the plug having a second areaand a second perimeter equal to or greater than the first area and thefirst perimeter, respectively. A ferrite layer is disposed below themetal layer, and a vertical hole in the plug and extending through theferrite layer has a third area and a third perimeter less than the firstarea and the first perimeter, respectively. A booster antenna isattached to the ferrite layer for enhancing RF transmission with the ICmodule.

The first cut out region may have dimensions nominally equal to, butslightly greater than D1, the first area, and the first perimeter, tofacilitate a snug fit of the IC module disposed within the first cut outregion. The second cut out region may have a second area and secondperimeter greater than the first area and first perimeter, respectively,extending vertically until a distance D1 from the top surface, with theplug disposed within the second cut out region. The metal layer may havea thickness D greater than D1, and the opening in the metal layer mayextend for a full thickness of the metal layer in which is located theIC module mounted on the plug extending between the top and bottomsurfaces of the metal layer.

The second area and the second perimeter of the opening in the metallayer may be respectively greater than the first area and the firstperimeter, and the plug may be attached to the metal layer and may fillthe opening within the metal layer. The plug may have a first cut outregion having an area and a perimeter nominally equal to but slightlygreater than the first area and the first perimeter, respectively. Theplug may extend for a depth nominally equal to but slightly greater thanD1 below the top surface for accommodating the IC module with a snugfit. The plug may have a second region below the first region whichextends until the bottom surface of the metal layer. A masking layer maybe disposed over the top metal surface and any exposed portion of theplug.

The booster antenna may be configured to inductively couple to the ICmodule or may be physically connected to the IC module.

A method of making one embodiment of a card as described herein maycomprise the steps of selecting the metal layer, cutting out the secondcut out region in the metal layer starting from the bottom surface ofthe metal layer, and securely attaching the plug within the second cutout region. The plug is designed to fit in and fill the second cut outregion. The first cut out region is cut in said top surface of the metallayer overlying said second cut out region, and disposed symmetricallywith respect to the second cut out region. The IC module is inserted andsecurely attached within the first cut out region with the contacts ofthe IC module positioned along the same horizontal plane as the topsurface of the metal layer. The ferrite layer is attached to the bottomsurface of the metal layer, and the booster antenna layer is attached tothe ferrite layer. The vertical hole is then formed in the plug and theferrite layer. The method may further comprise laminating the metallayer, the ferrite layer and the booster antenna layer. The method mayfurther include the step of physically connecting the booster antenna tothe IC module.

A method of making another embodiment a card as described herein maycomprise the steps of selecting the metal layer, forming the opening,securely attaching the plug within the opening; and inserting andsecuring attaching the IC module within the plug first cut out region.The ferrite layer is attached to the bottom surface of the metal layer,and the booster antenna layer is attached to the ferrite layer; and thevertical hole is formed in the plug and the ferrite layer. The methodmay further comprise forming a masking layer over the top metal surfaceand any exposed portion of the plug. The method may comprise laminatingthe metal layer, the ferrite layer and the booster antenna layer.

Another aspect of the invention comprises a metal smart card with dualinterface capability comprising a metal layer of thickness D having atop surface and a bottom surface extending parallel to each other, thetop surface defining a horizontal plane. The card includes an integratedcircuit (IC) module having a top region with contacts configured forphysical contact with a card reader. The IC module is also configuredfor contactless radio frequency (RF) communication with a card reader,and has a first periphery, a first area, and a thickness D1, wherein D1is less than D. A plug of non-RF-impeding material has a secondperiphery and a second area equal to or greater than the first peripheryand a first area, respectively. An opening in the metal layer extendsfor a full thickness of the metal layer. The IC module is mounted on theplug disposed in the opening, the IC module and the plug extending inthe vertical direction between the top and bottom surfaces of the metallayer with the contacts of the IC module positioned along the samehorizontal plane as the top surface of the metal layer. The opening inthe metal layer has a first region at and just below the top surface foraccommodating the IC module and a second region below the first regionwhich extends until the bottom surface of the metal layer. The openingin the first region has lateral dimensions nominally equal to butslightly greater than the first area and the fist periphery for a depthnominally equal to but slightly greater than D1. The second region has asecond area and a second periphery for a depth of a remaining thicknessof the card beneath the first region. The IC module fits in and fillsthe opening in the first region and the plug fits in and fills theopening in the second region. The second area and the second peripheryare respectively greater than the first area and the first periphery. Amasking layer is disposed over the top metal surface and any exposedportion of the plug. A ferrite layer is disposed below the metal layer.A vertical hole in the plug extends through the ferrite layer. Thevertical hole has a third area and a third periphery less than the firstarea and the first periphery, respectively. A booster antenna isattached to the ferrite layer for enhancing RF transmission with the ICmodule. The booster antenna may be configured to inductively couple tothe IC module or may be physically connected to the IC module.

Still another aspect of the invention comprises a card comprising ametal layer having a top surface and a bottom surface extending parallelto each other. A first region cut out in the top surface of the metallayer has a first depth, a first perimeter and a first area. Anintegrated circuit (IC) module is snugly secured within the first cutout region. The IC module has contacts positioned along the top surfaceof the metal layer and is configured to communicate using RFtransmission to enable contactless operation. A second cut out regionextends from the bottom surface of the metal layer until the first depthfrom the top surface. The second cut out region extends vertically belowthe first cut out region and generally in a symmetrical manner withrespect to the first cut out region. The second cut out region has asecond area and a second perimeter greater than the first area and thesecond perimeter. A plug comprising non RF impeding material is snuglysecured within the second cut out region. A ferrite layer is disposedbelow the metal layer. A a vertical hole in the plug extends through theferrite layer, and has having a third area and a third periphery lessthan the first area and the first periphery, respectively. A boosterantenna is attached to the ferrite layer for enhancing RF transmissionwith the IC module. The booster antenna may be configured to inductivelycouple to the IC module or may be physically connected to the IC module.

Still another aspect of the invention comprises a card comprising ametal layer having a top surface and a bottom surface extending parallelto each other, and a thickness extending between the top surface and thebottom surface.

A ferrite layer is disposed below the metal layer. A booster antenna isdisposed below the ferrite layer for enhancing RF transmission with theIC module. An opening in the metal layer and the ferrite layer extendsto the booster antenna layer. An integrated circuit (IC) module having afirst area, a first perimeter, and a first depth that is less than thethickness of the metal layer is disposed within the opening, hascontacts positioned along the top surface of the metal layer and isconfigured to communicate using RF transmission to enable contactlessoperation. A physical electrical connection between the booster antennaand the IC module extends through the opening. The card may have anon-conductive liner in the opening in the metal layer. Thenon-conductive liner may comprise a plug of non-conductive material,wherein the plug has a second area and a second perimeter greater thanthe first area and the first perimeter, respectively. The plug may havethe second area and the second perimeter for a depth that extends for afull thickness of the metal layer and further comprises a cut out regionin the plug nominally equal to but slightly greater than the first area,the first perimeter, and the first depth for receiving the IC module inthe cut-out region. The plug may further have a through-hole extendingfrom the cut-out region for a remaining depth of the plug and connectingto the opening in the ferrite layer. The through-hole in the plug andthe opening in the ferrite layer have a third area and a third perimeterless than the first area and the first perimeter, respectively.

The opening may be a stepped opening having a first region nominallyequal to but slightly greater than the first area, the first perimeter,and the first depth so as to fit the IC module snugly therein. A secondregion has the second area and the second perimeter for a depth thatextends from the bottom surface of the metal layer for a distance lessthan a full thickness of the metal layer. The plug is disposed only inthe second region, and has a through-hole connecting to the opening inthe ferrite layer. The through-hole in the plug and the opening in theferrite layer have a third area and a third perimeter less than thefirst area and the first perimeter, respectively.

The opening may have an area and a perimeter that is nominally equal tobut slightly greater than the first area and the second area, and thephysical electrical connection between the booster antenna and the ICmodule may comprise a connection module disposed between the boosterantenna and the IC module. The booster antenna may have first and secondconnection nodes and the IC module may have third and fourth connectionnodes. The connection module may have mating first and second connectionnodes on a first surface thereof and third and fourth connection nodeson a second surface thereof. A first conductive trace connects the firstand third nodes and a second conductive trace connects the second andfourth nodes.

Yet another aspect of the invention is a method of making the cardembodiment described above, the method comprising the steps of selectingthe metal layer, attaching the ferrite layer beneath the metal layer,attaching the booster antenna layer beneath the ferrite layer, formingthe opening in the metal layer extending through the ferrite layer tothe booster antenna, and inserting and securely attaching said IC modulein the opening with the contacts of the IC module positioned along thesame horizontal plane as the top surface of the metal layer and the ICmodule physically connected to the booster antenna layer.

The method may comprise first forming the opening in the metal layer anddisposing a plug in at least a portion of the opening in the metallayer, at least a portion of the plug having a second area and a secondperimeter greater than the first area and the first perimeter,respectively, and creating a through-hole in the plug and the opening inthe ferrite layer, the through-hole in the plug and the opening in theferrite layer having a third area and a third perimeter less than thefirst area and the first perimeter, respectively. The method maycomprises first forming a bottom portion of the opening in the metallayer for less than a full thickness of the metal layer, the bottomportion having the second area and a second perimeter, and disposing theplug in the bottom portion of the metal layer, then creatingthrough-hole in the plug and the opening in the ferrite layer, thethrough-hole in the plug and the opening in the ferrite layer having athird area and a third perimeter less than the first area and the firstperimeter, respectively. The method may comprise first laminating themetal layer, the ferrite layer beneath the metal layer, and the boosterantenna layer together, then forming the opening in the metal layerextending through the ferrite layer to the booster antenna, wherein theopening has an area and a perimeter nominally equal to but slightlygreater than the first area and the first perimeter, respectively.

The method may comprise disposing a liner in the opening prior toinserting and securely attaching the IC module in the opening andconnecting the IC module to the booster antenna layer. The boosterantenna layer may have a plurality of connection nodes and the IC modulemay have a plurality of connection nodes, wherein the method furthercomprises disposing a connector in the opening prior to inserting the ICmodule in the opening, the connector having mating nodes for connectingto the booster antenna connection nodes and the IC module connectionnodes.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be understood more completely from the followingdetailed description of presently preferred, but nonethelessillustrative, embodiments in accordance with the present invention, withreference being had to the accompanying drawings, which are not drawn toscale, but in which like reference characters denote like components;and

FIG. 1 is a simplified, isometric diagram of a smart card 10 with ametal layer 30, embodying the invention;

FIG. 1A is a highly simplified, idealized isometric diagram of anintegrated circuit (IC) module capable of contactless and contactoperation intended for use in making smart cards embodying theinvention;

FIG. 1B is a simplified idealized cross sectional diagram of the ICmodule of FIG. 1A used in the card shown in FIG. 1;

FIG. 2 includes cross sectional diagrams of various processing steps(STEP 1 through STEP 7A or 7B) to form a card embodying the invention;

FIG. 3A is a simplified cross sectional diagram of a card being made asshown in step 5 of FIG. 2;

FIG. 3B is a top view of a card being formed as shown in FIG. 3A with aplug (34) and the opening (36) formed in the plug;

FIG. 3C is a top view of the top layer of a card embodying the inventionformed in accordance with the process shown in FIG. 2;

FIG. 4 includes cross sectional diagrams of various processing steps(STEP 1 through STEP 5A or 5B) to form a card according to anotheraspect of the invention;

FIG. 5A is a cross sectional diagram corresponding to step 4 of FIG. 4showing a plug and openings formed in the plug prior to insertion of anIC module;

FIG. 5B is a top view of a card having the cross section shown in FIG.5A showing the plug and openings formed in the plug prior to insertionof an IC module formed in accordance with FIG. 4;

FIG. 5C is a top view of a card formed according to the process stepsshown in FIG. 4 and as shown in FIGS. 5A and 5B with an IC moduleinserted in the opening for the module; and

FIG. 6 is a cross-sectional diagram showing a masking layer formed on acard such as the one shown in FIG. 5C.

FIG. 7 includes cross sectional diagrams of various processing steps(STEP 1 through STEP 3) to form a card according to another aspect ofthe invention;

FIG. 8 is a cross sectional diagram of an exemplary connector for use inconnection with the embodiment depicted in FIG. 7 STEP 3.

DETAILED DESCRIPTION

An integrated circuit (IC) module 7 having multiple contacts as shown inFIG. 1A is to be mounted in, and on, a card 10 as shown in FIG. 1 withthe top surface of the IC module and its contacts generally flush withthe top surface of the card. By way of example it is shown that thelength, width and depth of the card may respectively be approximately3.37 inches by 2.125 inches by 0.03 inches. For purpose of illustrationand the discussion to follow, we assume, as shown in FIG. 1A, that theIC module has a depth D1, a length L1 and a width W1. Modules such as ICmodule 7 are commercially available, for example, from Infineon or NXP.The lateral dimensions of some of these modules were approximately 0.052inches by 0.47 inches with a depth ranging from 0.005 inches to morethan 0.025 inches. These dimensions are purely illustrative and ICmodules used to practice the invention may be greater or smaller insize.

As shown in FIG. 1B, IC module 7 contains an internal microprocessorchip 7 a, a chip antenna 7 b and a contact pad 7 c. Pad 7 c may be aconventional multi-contact pad used in contact-type smart cards and ispositioned to engage contacts in a contact card reader (not shown) whenthe smart card is inserted therein. An epoxy blob 7 d encapsulates thebottom side of the IC module. The epoxy blob allows the IC module to beeasily attached (e.g., by gluing) to an underlying surface. Theinvention is not limited to any particular method for attachment of thechip to the module, which attachment may, for example, instead be a flipchip connection.

As noted above, one aspect of the invention is directed to themanufacture of a smart metal card having dual interface capability.Preferably, the card also has a top surface free of any bumps ordepressions, except for: (a) the IC module and its contacts, and/or (b)any design or texture intentionally formed on the top surface. The cardcan be made to have a highly aesthetic, smooth and visually pleasingappearance even though the card has dual interface capability (i.e.,contact and contactless capability). The contacts of the IC module arelocated along an exterior surface of the card. Typically, the contactsare located along the top surface of the card; although the contacts maybe located along the bottom surface of the card. A cut out (opening) inthe metal layer underlies and surrounds the IC module. Ideally, thesecut outs (openings) in the metal layer are formed without affecting thesmooth, aesthetic, exterior (e.g., top) appearance of the card.

A method of forming a card in accordance with the invention includes thestructure and processing steps illustrated in FIG. 2.

STEP 1—A metal layer 30 is selected to serve as the top layer of a card10 (as shown in step 1 of FIG. 2). The metal layer 30 has a top (front)surface 301 and a bottom (back) surface 302; the front and back surfacesare generally parallel to each other. The thickness (D) of the metallayer 30 may range from less than 0.01 inches to more than 0.02 inches.In one embodiment the metal layer 30 comprises stainless steel and itsthickness is 0.0155 inches. Metal layer 30 may, by way of example andnot by way of limitation, comprise iron, tantalum, aluminum, brass,copper or any alloy or compound thereof.

STEP 2—A pocket 32 is formed along the underside of layer 30. It may bereferred to as a reverse pocket formed starting from the bottom surfaceof metal layer 30 (as shown in step 2 of FIG. 2). The pocket 32 may beformed in any known manner including, but no limited to: milling,casting, 3D printing, laser cutting, water jet electro-discharge (EDM).The pocket 32 has a top 321 which ends a distance (or thickness) D1below top surface 301, where D1 is typically equal to (or nearly equalto) the depth of the IC module 7. The depth (thickness) D2 of pocket 32is then equal to (D-D1) inches. D2 will generally always be set to equalthe depth D of the metal layer 30 minus the thickness D1 of the ICmodule used to form the card. The pocket 32 may be of regular orirregular shape, a rectangular solid or a cylinder whose planarprojection in the horizontal plane may be a square, a rectangle or acircle. The lateral dimensions [length (12) and width (W2)] of thepocket 32 can be, respectively, equal to or greater than the lateraldimensions [length L1 and width W1] of the IC module as furtherdiscussed below. In the embodiments L2 and W2 are shown to be,respectively, greater than L1 and W1, but that is not a necessarycondition.

STEP 3—A plug 34 of any material which does not substantially interferewith RF transmission (e.g., any non-metallic material, or even amaterial such as tungsten or a composite thereof) is formed or shaped toconform to the dimensions of the milled pocket 32 and is inserted in thepocket to fill the milled (cut out) region (as shown in step 3 of FIG.2). As discussed below the plug functions to electrically isolate andinsulate the IC module from the metal layer and to also physicallysecure the IC module. The interior of the pocket 32 and/or the exteriorof the plug 34 is/are coated with a suitable adhesive (e.g., such asacrylic or acrylic modified polyethylene, cyanoacrylate, siliconeelastomer, epoxy) so the plug 34 adheres firmly to the walls of thepocket throughout the processing of the metal layer in the formation ofthe card. The plug 34 may be made of any material that does notsignificantly impede radio frequency (RF) transmission, such as athermoplastic material, such as PET, PVC or other polymer, or a curableresin or epoxy, a ceramic, or even tungsten.

STEP 4—As shown in step 4 of FIG. 2, an adhesive layer 42 is used toattach a ferrite layer 44 to the back surface 302 of layer 30. Theferrite layer 44 is placed below the metal layer 30 to act as a shield(reflector) to prevent/reduce metal layer 30 from interfering with radiofrequency radiation to and from the smart card. Ferrite layer 44decreases the “shorting” effect of metal layer 30 for enablingtransmission or reception via antenna 47. Those skilled in the art willappreciate that it would also be possible to form or lay out the ferritematerial in a different manner.

Also, an adhesive layer 46 is used to attach a plastic (e.g., PVC) layer48 which contains and/or on which is mounted a booster antenna 47. Layer48 may be made of PVC or polyester and may be between 0.001 and 0.015inches thick. The windings of booster antenna 47 may range from lessthan 80 microns to more than 120 microns in diameter and may be securedto layer 48 by ultrasonic welding or heating the wire prior to placingit in contact with the plastic layer or by any other suitable process. Alayer 52, which includes a signature panel and a magnetic stripe, may beattached to layer 48 before or after lamination. Layers 42, 44, 46, 48(and possibly 52) may be formed as a sub-assembly 40 and attached to thebottom side 302 of metal layer 30.

STEP 5—The assembly comprising layers 30, 42, 44, 46 and 48 is laminated(as indicated in step 5 of FIG. 2) to form a card assembly 50.

STEP 6—A hole (or opening) 36 is then formed (e.g., by milling) throughthe metal 30 to a depth D1 from the top surface and, concurrently, ahole 362 is then formed in plug 34, (e.g., by drilling about the centerof the plug 34) and through the underlying layers 42, 44 and 46 untillayer 48, as shown in step 6 of FIG. 2. The lateral dimensions of hole36 formed in the metal layer 30 are designed to correspond to thedimensions L1 and W1 of the IC module 7 so the IC module can be insertedin the hole (opening) 36. The lateral dimensions of the hole 362 formedin the plug 34 will be L3 and W3, where L3 and W3 are less than L1 andW1. So made, plug ledges 341 a will provide support for the IC moduleand keep it at its designed height of D1 below the top card surface.

STEP 7—The IC module may then be snugly inserted and attached to thesides of opening 36 and to top 341 a of the plug 34. That is, the ICmodule may be inserted with tight clearance and glued in place. Thesmaller hole (opening) 362 formed below hole 36 accommodates the rear(bottom) end of module 7. Hole 362 extends vertically down throughferrite layer 44 and is made sufficiently wide (a) to enable RF signalsto pass between antenna 47 and the chip antenna 7 b for embodimentsusing RF coupling between antenna 47 and chip antenna 7 b, as shown inSTEP 7A, or (b) to enable physical connections 500 between the antenna47 and the chip antenna, in embodiments with physical connections asshown in STEP 7B.

In embodiments with physical connections, the connections may be in theform known in the art, including but not limited to continuous wiresbetween the wires of the antenna winding and the corresponding wires ofthe module, or connection points on the antenna layer that mate with aconnector constructed to span the distance between the nodes and theconnection points on the module, such as is illustrated in FIGS. 7 and 8and described in more detail herein later. Although in the case of aphysical connection, it may not be as beneficial to have anon-RF-impeding material between the chip and the antenna layer, theremay still be advantages to having, in particular, a non-metallicmaterial lining the channel. Such materials enable the use ofnon-insulated connectors 500, if desired. There are multiple ways toform electrical connections between the module and an antenna. Theantenna may comprise a wire (e.g. copper or another metal) or a planarantenna. An exemplary planar antenna may be etched or printed, typicallyin a roll-to-roll fashion. The direct connection to the module may beformed via anisotropic (ACF) tape, conductive adhesive, solder or solderbump methods.

With respect to the operation of the card, booster antenna 47 isdesigned to capture radio frequency energy generated by an associatedcard reader (not shown) and to communicate with the card reader. Bydesign, module antenna 7 b is sufficiently close to couple inductivelywith antenna 47 (in inductively coupled embodiments), thereby providingsignals from antenna 47 to chip 7 a, while keeping the chip electricallyisolated from antenna 47. In operation, ferrite layer 44 shields metallayer 30, to make it possible for radio frequency radiation to enter andbe emitted from card 10. In operation, ferrite layer 44 shields metallayer 30, to make it possible for radio frequency radiation to enter andbe emitted from card 10. Booster antenna 47 is designed to capture radiofrequency energy generated by an associated card reader (not shown) andto communicate with the card reader.

As shown in Step 7A of FIG. 2, an IC module 7 which, as shown in FIG.1B, includes a chip 7 a, a chip antenna 7 b and a set of contacts 7 c ispositioned within hole 36. The IC module 7 is glued in place completingthe formation of an exemplary card.

To appreciate the appearance of the card as finally formed reference isfirst made to FIG. 3A (which is essentially a copy of STEP 6 of FIG. 2)and to FIG. 3B. FIG. 3B is a top view of the card being formed showingthe openings (36 and 362) formed in the metal and the plug. Note thehole 36 in metal layer 30 will have edge(s) 361 and the hole 362 in theplug and the underlying layers 42, 44, 46 will have edge(s) 345/367. Theportion of the plug 34 below region 341 b and the outer edge 343 of theplug will not be seen. Hence, outer edge 343 is shown with dashed lines.

The resultant FIG. 3C is a top view of a card 10 showing the module 7mounted and inserted in the top of the card. The plug 34 is not seensince it is underneath the metal layer. Thus, the top surface of a card10 formed in accordance with the process steps shown in FIG. 2 displaysa completely smooth unbroken metal surface (except for the contact padof the IC module). The underlying plug is covered (hidden) by anoverlying metal region. Significantly, the card having the desiredbeautiful physical appearance can function as a wireless (contactless)card or as a contact card.

It should be understood that as described herein with both the chip andthe opening for receiving the chip having nominal dimensions L1, W1,that the chip is slightly less than L1, W1 and/or the opening isslightly more than L1, W1, by a commercially acceptable tolerance (e.g.0.0005-0.002″), such that the chip fits snugly within the hole with thecommercially acceptable tolerance. Preferably, however, the gap betweenthe chip and the sides of the opening is minimized (sufficient toprevent shorting between the contacts and the sides of the opening inthe metal body, but not substantially more) to provide a “snug” fit,primarily for aesthetic purposes. Thus the term “nominally equal to butslightly greater than” referencing an opening for receiving the ICmodule refers to an opening that includes only this commerciallyacceptable tolerance, without more, as would be understood by those ofskill in the art from the descriptions herein. Unlike other designsknown in the art, a deliberately large gap between the chip and thesides of the opening is not required to provide suitable RFfunctionality.

The dimensional tolerances of the various holes/openings and of thecomponents are preferably close enough so that on a platen laminationall parts fuse together with no airspace or sinks in the outwardappearance of the card.

As shown in the Figures, metal layer 30 has a cut out 36 formed in itstop surface. The thickness/depth D1 of cut out 36 is made substantiallyequal to (i.e. nominally equal to but slightly larger than) the depth ofthe IC module 7. The hole/opening 36 is machined through metal layer 30dimensioned to receive module 7, which is secured therein, as bybonding. Module 7 contains a microprocessor chip 7 a (internally), achip antenna 7 b and a contact pad 7 c. Pad 7 c is a conventionalcontact pad used in contact-type smart cards and is positioned to engagecontacts in a card reader when the smartcard is inserted therein.

By design, in the embodiment depicted in FIG. 2, plug 34 issubstantially wider than module 7. Preferably, plug 34 extends at least0.04 laterally beyond either side of module 7. This prevents the metalin substrate 30 from interfering with communication between the card andchip. However, the plug does not have to be wider than module 7 (i.e.,its lateral dimensions L2, W2 need not be greater than those of themodule L1,W1).

Module 7 is positioned vertically within metal layer 30 so as to providea contact pad 7 c along the top metal surface to realize the contactfunctions of the dual interface. Moreover, positioning module 7 on plug34 which is made larger (though not necessarily so) in area than themodule 7 makes it possible to decrease interference in the radiocommunication between module antenna 7 b and the booster antenna 47.

Alternatively, cards embodying the invention may be formed as shown inFIGS. 4, 4A, 5A, 5B, 5C and 6. These cards differ from those discussedabove in that a plug is formed whose thickness is equal to the thicknessof the metal layer. That is, there is no recessed pocket.

As shown in FIG. 4, a card formed in accordance with this aspect of theinvention may include the following processing steps and structure:

STEP 1—A metal layer 30 is selected (as shown in STEP 1 of FIG. 4) whichis intended to serve as the top layer of a card 10. The metal layer 30has a top (front) surface 301 and a bottom (back) surface 302 and athickness (D) which may range from less than 0.01 inches to more than0.02 inches. Metal layer 30 may have the same characteristics andproperties as metal layer 30 shown and discussed above.

STEP 2—A hole 420 of depth D is formed in the metal layer 30 (as shownin step 1 of FIG. 4). The lateral dimensions of the hole are L2 and W2(see FIGS. 5A and 5B). The hole 420 may be formed in any known manner(e.g., casting or milling). The hole 420 may be a regular or irregularsolid cube, or a cylinder whose planar projection in the horizontalplane may be a square, a rectangle or a circle or an irregular shape. Inthe embodiment shown in FIG. 4, the lateral dimensions [length (L2) andwidth (W2)] of the hole 420 are respectively greater than the lateraldimensions [length L1 and width W1] of the IC module as furtherdiscussed below. Generally, L2 is greater than L1 (by at least 0.04inches and W2 is greater than W1 (by at least 0.04 inches). However, asnoted above, L2 may be made equal to L1, and W2 may be made equal to W1.The advantage of making L2 and W2, respectively, larger than L1 and W1is to provide greater separation between the metal layer and the ICmodule and thus enhance RF transmission and reception.

A plug 434 of any material like plug 34 which does not interfere with RFtransmission is formed or shaped to conform to the dimensions of thehole 420 to fill the cut out region. Plug 434 is processed and functionsto secure the IC module. The interior walls of the hole 420 and/or theexterior walls of the plug 434 is/are coated with a suitable adhesive sothe plug 434 adheres firmly to the walls of the hole throughout theprocessing of the metal layer in the formation of the card. The plug 434may be made of any thermoplastic material such as PET, PVC or otherpolymer or any material such as epoxy resins and a ceramic.

STEP 3—An adhesive layer 42 is used to attach a ferrite layer 44 to theback surface 302 of layer 30. An adhesive layer 46 is used to attach aplastic (e.g., PVC) layer 48 which contains and/or on which is mounted abooster antenna 47 to the ferrite layer. Layers 42, 44, 46, and 48 andthe booster antenna 47 are formed in a similar manner as thecorresponding number components shown in FIG. 2 and serve the same orsimilar functions. The assembly comprising layers 30, 42, 44, 46 and 48is laminated to form a card assembly 350.

STEP 4—A T-shaped hole/opening 436 is then formed through the plug 434.The hole 436 is formed by milling, drilling and/or any other suitablemeans. The top portion 436 a of T-shaped hole 436 is formed to havelateral and depth dimensions to accommodate the IC module. Where thedimensions of IC module 7 are L1 by W1 by D1 the top portion of 436 awill be formed to be just about L1 by W1 by D1 to enable the IC moduleto be snugly inserted within the hole 436 a and to be glued in place.The bottom portion 436 b of the hole 436 formed in plug 434, (bydrilling vertically down about the center of the plug 434) extendsthrough the underlying layers 42, 44 and 46 and until layer 48, as shownin STEP 4 of FIG. 4. The lateral dimensions of hole 436 b formed in plug434 are made large enough (a) to enable sufficient RF signals to passbetween booster antenna 47 and the IC chip module 7 to enable RFcommunication to take place reliably in inductively coupled embodimentsas depicted in FIG. 4 STEP 5A, and (b) to permit physical connections500 between the antenna module and the IC module, as depicted in FIG. 4STEP 5B. The physical connections may take any form, as discussed withrespect to the embodiment depicted in FIG. 2 STEP 7B. The lateraldimensions of the hole 436 b formed in the plug 434 are denoted as L3and W3, where L3 and W3 are less than L1 and W1. Note that making L3 andW3 less than L1, and W1, respectively, results in the formation ofledges 438, which will provide support for the IC module and keep it atits designed height of D1 below the top card surface 301. The IC module7 can be snugly inserted and attached (glued) to the ledges 438 and thetop interior walls of the plug 434.

STEPS 5A or 5B—IC module 7 which includes a chip 7 a and a chip antenna7 b and a set of contacts 7 c is positioned within hole 436 a is gluedin place. Physical connections extend between the booster antenna 47 andthe chip antenna 7 b in the embodiment depicted in Step 5B of FIG. 4.

FIG. 5A (not to be confused with Step 5A of FIG. 4) is an enlarged crosssectional diagram corresponding to step 4 of FIG. 4. FIG. 5B is a topview of a card showing the holes formed in the metal and the plug. FIG.5C is a top view of a card showing the module 7 mounted and inserted inthe top of the card. The smart metal card 10 can function as a wireless(contactless) card or as a contact card. Note that as shown in FIGS. 5A,5B and 5C the hole portion 436 a has an inner edge 440. The plug has anouter edge 442. As is evident from FIGS. 5B and 5C, the IC module 7 willcover openings 436 a and 436 b. As a result there is a space/area 450between edges 440 and 442 extending around the outer periphery of the ICmodule between the module 7 and the metal layer 30. The space/area 450may be objected to on aesthetic grounds as it detracts from thecontinuous metal layer (except for the necessary module contact pad).However, it should be appreciated that the space area 450 may enhance RFtransmission. The presence of space/area 450 and any depression or bumprelated to space 450 may be masked by the addition of a masking layer470, as shown in FIG. 6. Masking layer 470 may comprise any non-metalliclayer, such as but not limited to a PVC layer, as is known in the art,or other polymers, such as a polyester composite or polycarbonate, or avery thin ceramic layer. The foregoing construction with a masking layermay be acceptable in many instances. However, in instances where such asolution is still not acceptable or feasible, the solution is to revertto making cards as per the process steps shown in FIG. 2.

Thus, a problem with the smart cards formed in accordance with theprocess shown in FIG. 4 is that a portion of a plug may be seen. Theportion of the plug may mar the continuous appearance of the card and/oras a bump on the surface or as a depression. This may be so, even if amasking (concealing) layer 470 is formed over layer 30.

As taught and discussed with reference to FIG. 2, above, the spacing andany discontinuity in the metal surface (except for the IC module) areavoided by forming a recess pocket 32 in substrate 30 and filling therecess with a plug 34 which is not seen from the top of the card. Thus,in contrast to previous and other dual interface smart metal cards, theplug 34 does not appear as a bump on the surface or as a depression. Itis not visible when the card is viewed from the outside. The process ofFIG. 2 thus differs from the process of FIG. 4, in which a through hole420 is formed in the metal layer 30 and a plug 434 fills the hole 420.

In all the embodiments shown above, a plug separates an IC module from asurrounding metal layer and to position and secure the IC module withinthe card. In inductively coupled designs, the plug also enhances RFtransmissivity between the booster antenna and the IC module. Inphysically connected designs, the plug may also provide operationaladvantages. Openings for the plug and its positioning within the cardare designed to maintain the exterior of the card flat and visuallypleasant.

Embodiments with physical connections between the antenna module and theIC antenna may omit inclusion of a plug, however. As shown in FIG. 7, acard formed in accordance with this aspect of the invention may includethe following processing steps and structure:

STEP 1—A metal layer 30 is selected, which is intended to serve as thetop layer of a card 10. The metal layer 30 has a top (front) surface 301and a bottom (back) surface 302 and a thickness (D) which may range fromless than 0.01 inches to more than 0.02 inches. Metal layer 30 may havethe same characteristics and properties as metal layer 30 shown anddiscussed above. As shown in STEP 1 of FIG. 7, an adhesive layer 42 isused to attach a ferrite layer 44 to the back surface 302 of layer 30.An adhesive layer 46 is used to attach a plastic (e.g., PVC) layer 48which contains and/or on which is mounted a booster antenna 47 to theferrite layer. Layers 42, 44, 46, and 48 and the booster antenna 47 areformed in a similar manner as the corresponding number components shownin FIG. 2 and serve the same or similar functions. The assemblycomprising layers 30, 42, 44, 46 and 48 is then laminated to form a cardassembly 750. A layer 52, which includes a signature panel and amagnetic stripe, may be attached to layer 48 before or after lamination.Layers 42, 44, 46, 48 (and possibly 52) may be formed as a sub-assemblyand attached to the bottom side 302 of metal layer 30.

STEP 2—A hole 720 is formed through the metal layer 30 and layers 42,44, 46, until layer 48. Although shown stopping at layer 48, in someembodiments, the hole may also cut through layer 48 (this is true of theother embodiments described and depicted herein as well). The lateraldimensions of the hole are nominally equal to but slightly larger thanthe lateral dimensions of the IC module (e.g. L1 and W1). The hole 720may be formed in any known manner (e.g., milling, drilling and/or anyother suitable means). The hole 720 may be a regular or irregular solidcube, or a cylinder whose planar projection in the horizontal plane maybe a square, a rectangle or a circle or an irregular shape. The hole mayalso have a stepped configuration (T-shaped in cross section), with arelatively wider portion facing a top surface and a relatively narrowerportion facing a bottom surface of the card, such that the chip wheninserted rests on a metal shelf in the card body formed at thetransition from the relatively narrower portion to the relatively widerportion. In the embodiment shown in FIG. 7, the lateral dimensions[nominally length (L1) and width (W1)] of the hole 420 are only slightlygreater than the lateral dimensions [also nominally length L1 and widthW1] of the IC module as discussed herein, in which the differencebetween the hole and the module dimensions conforms to a commerciallyacceptable tolerance.

STEP 3—Physical connections 700 are provided between the antenna moduleand the IC module, as depicted in FIG. 7 STEP 3. The physicalconnections may take any form, as discussed with respect to theembodiment depicted in FIG. 2 STEP 7, except because hole 720 is notlined by a non-conductive plug, the physical connections may beinsulated to avoid shorting against the walls of the hole. In oneembodiment, depicted in FIG. 7 STEP 2 ALT A, a liner 760 may be disposedon the sides of the hole, such as with a coating or an annular pluginserted in the hole, prior to making wired connections. Liner 720 mayhave a length sufficient to cover the entire hole beneath the insertiondepth of the IC module to the booster antenna, or it may cover only themetal portion of the hole. In another embodiment, the at least theportion of the physical connections 700 b disposed within the portion ofthe hole in the metal body may be insulated wires (e.g. conductive wirescoated with a non-conductive coating). In another embodiment, depictedin FIG. 7 STEP 3, booster antenna layer 48 has connection points 702 afor connection to the antenna via connection segments 700 a, and the ICmodule has corresponding connection points 704 a. As depicted in FIG. 8,a modular connector 710 has mating connection points 702 b and 704 b,respectively, for mating with the corresponding connection points in theantenna layer and the IC chip, with electrically conductive connectionsegments 700 b connecting the connection points 702 b and 704 b withinthe connector. The lateral dimensions of the connector 710 are alsonominally L1 and W1, within essentially the same commercial tolerance asthe IC module, to permit snug insertion within the hole 720. Theconnector may also have an inset with dimensions L3 and W3 less than L1and W1, respectively, resulting in the formation of ledges 738, whichprovide support for the IC module and keep it at its designed height ofD1 below the top card surface 301. Likewise, in the embodiment depictedin FIG. 7 STEP 2 ALT A, the liner 760 may be sized to provide anequivalent ledge. The IC module 7 can be snugly inserted and attached(glued) to the ledges 738 and the top interior walls of the inset withinconnector 710. It should be understood that although depicted inconnection with this embodiment, a similar connector structure may beemployed for any of the other embodiments depicted herein for makingphysical connections, with the periphery and lateral area of theconnector matched to the respective periphery and lateral area of thehole into which it is inserted. In the embodiment depicted in FIG. 7,STEP 3, the body of the connector preferably comprises a non-conductivematerials, so as to avoid making any electrical connections between thetraces 700 b and/or between the traces and the walls of the hole 720 inthe metal portion of the card.

As shown in STEP 3 of FIG. 7, IC module 7, which includes a chip 7 a anda chip antenna 7 b and a set of contacts 7 c, is positioned within hole436. Physical connections 700 a,b extend between the booster antenna 47and the chip antenna 7 b.

Although discussed herein in terms of dimensions L1, W1 relative todimensions L2, W2 relative to dimensions L3, W3 in various places, asnoted herein, the invention is not limited to rectangular embodiments,as noted above. Accordingly, when discussed in terms of one elementhaving greater dimensions than another, it should be understood that innon-rectangular embodiments, reference to a structure with relativelylarger dimensions refers to a structure having relatively larger areawith a relatively larger perimeter located relatively radially outwardof the comparative structure, which is also inherently true of therectangular embodiments referred to in the examples.

Although the invention is illustrated and described herein withreference to specific embodiments, the invention is not intended to belimited to the details shown. Rather, various modifications may be madein the details within the scope and range of equivalents of the claimsand without departing from the invention.

What is claimed:
 1. A transaction card comprising: a metal layer havingopposite first and second surfaces and a thickness; a first cut outregion in the first surface of said metal layer, said first cut outregion having a depth less than the thickness of the metal layer; anintegrated circuit (IC) module having a first portion secured within thefirst cut out region; a second cut out region extending from the firstcut out region to the second surface of said metal layer, said secondcut out region defining a non-RF-impeding volume and having a perimetergreater than the perimeter of the first cut out region; one or moreadditional layers stacked on the second surface of the metal layer; anda channel extending between at least one of the one or more layers andthe IC module.
 2. The transaction card of claim 1, wherein the perimeterof the second cut out region is disposed symmetrically relative to theperimeter of the first cut out region.
 3. The transaction card of claim1, wherein the one or more additional layers stacked on the secondsurface of the metal layer includes a booster antenna layer.
 4. Thetransaction card of claim 1, wherein the one or more additional layersstacked on the second surface of the metal layer includes an RFshielding layer.
 5. The transaction card of claim 4, wherein the RFshielding layer comprises ferrite.
 6. The transaction card of claim 1,wherein the one or more additional layers stacked on the second surfaceof the metal layer includes an adhesive layer.
 7. The transaction cardof claim 1, wherein a second portion of the IC module is disposed withinthe channel.
 8. The transaction card of claim 7, wherein the secondportion of the IC module disposed within the channel comprises a moduleantenna.
 9. The transaction card of claim 8, wherein the one or moreadditional layers stacked on the second surface of the metal layerincludes a booster antenna layer, and wherein the module antenna iscoupled to the booster antenna.
 10. The transaction card of claim 9,wherein the module antenna is inductively coupled to the booster antennalayer.
 11. The transaction card of claim 9, wherein the module antennais physically coupled to the booster antenna layer.
 12. The transactioncard of claim 11, wherein the module antenna is physically coupled tothe booster antenna layer via a welded connection.
 13. The transactioncard of claim 1, wherein the non-RF-impeding volume comprises a plug ofnon-RF-impeding material secured within said second cut out region. 14.The transaction card of claim 13, wherein the plug has a geometrycorresponding to a geometry of the second cut out region.
 15. Thetransaction card of claim 13, wherein the plug comprises PVC.
 16. Thetransaction card of claim 13, wherein a portion of the channel isdefined within the plug.
 17. The transaction card of claim 16, wherein asecond portion of the IC module is disposed within the portion of thechannel in the plug, the second portion of the IC module comprising amodule antenna.
 18. The transaction card of claim 1, wherein the metallayer comprises stainless steel.
 19. The transaction card of claim 1,wherein the metal layer and the one or more additional layers stacked onthe second surface of the metal layer are laminated to one another. 20.The transaction card of claim 1, wherein the one or more additionallayers stacked on the second surface of the metal layer comprise atleast one of an adhesive layer, an RF shielding layer, and a boosterantenna layer.
 21. The transaction card of claim 1, wherein the ICmodule is a dual-interface IC module.
 22. A method of making thetransaction card of claim 1, comprising the steps of: providing themetal layer, and forming the first cut out region, the second cut outregion, and the channel by milling processes.
 23. The method of claim22, further comprising: securing a plug of non-RF-impeding materialwithin said second cut out region, wherein the process of forming thechannel includes milling a portion of the channel in the plug.
 24. Atransaction card comprising: a stainless steel layer having oppositefirst and second surfaces and a thickness; a first cut out region in thefirst surface of said stainless steel layer, said first cut out regionhaving a depth less than the thickness of the metal layer; an integratedcircuit (IC) module having a first portion secured within the first cutout region; a second cut out region extending from the first cut outregion to the second surface of said metal layer, said second cut outregion having a perimeter greater than the perimeter of the first cutout region; a PVC plug secured within said second cut out region; one ormore additional layers stacked on the second surface of the metal layer,the one or more layers comprising at least one adhesive layer, an RFshielding layer, and a booster antenna layer containing a boosterantenna; and a channel formed in the plug extending between at least oneof the one or more layers and the IC module, wherein a module antennaportion of the IC module is disposed within the channel and physicallycoupled to the booster antenna.